1. Field of the Invention
This invention relates to a suspension for an automobile and more particularly to a suspension having a cylinder and a piston rod projecting therefrom and provided with a car height adjusting mechanism.
2. Description of the Prior Art
One of apparatuses for adjusting the car height of automobile provided with a strut type suspension manually and without use of air pressure is disclosed, for example, in the specification of U.S. Pat. No. 3,603, 575. In this apparatus, a coil spring is held between a ring screwed onto the outer periphery of a tubular housing covering fixedly a cylinder and a disk fixed to a piston rod projecting from the cylinder. When the ring is turned, the piston rod extends or retracts by the action of the coil spring to adjust the car height.
In said apparatus, however, the ring has to be rotated under the condition of contacting an end of the coil spring, so that frictional force acting between the ring and coil spring is large enough and thereby the car height is not easily adjusted by turning the ring against such frictional force. Also, irrespective of the easiness of the car height adjustment, the weight of the suspension is disadvantageously increased since said housing covers the whole cylinder.
Another apparatus for ajusting manually the car height is disclosed in Japanese Utility Model publication No. 48-41382. In this apparatus, the inner periphery of a mounting block securely fixed to a car body is threaded, and a hollow screw member inserted fixedly into a piston rod projecting from a cylinder of a shock absorber is screwed in said inner periphery of the mounting block. An upper seat holding the upper end of a coil spring is held by the lower end of said hollow screw member, and the upper end of the hollow screw member is provided with an adjusting portion for engaging a tool to turn the hollow screw member and thus adjust the car height.
In said apparatus, however, since said hollow screw member is arranged above the upper seat, the total length of the car height adjusting apparatus is disadvantageously elongated.